60 research outputs found
Tensile Properties of Aluminium/Graphite Composite Through Simulation Analysis
Composite materials are manufactured by the combination of two or more distinct materials. The different materials form the distinct characteristics of the composites. Solid and stiff reinforcement is often inserted into a ductile matrix in aluminium-reinforced composites, which aim to increase mechanical properties, particularly strength, strength-to-weight ratio etc. This research study was focused on detail around the preparation data and tensile properties of Al/Gr composites through simulation analysis. The mixtures of this composite with differ by weight percentages of Gr as reinforcement and with different types of samples were completed shows the differences by its tensile properties. Various weight percentage of Al/Gr composite which were (90/10, 80/20, 60/40). By conducting through this simulation analysis, it is found that when the value of weight percentages is different, the tensile properties will different either based on the strength. In recent years, conventional materials are replaced in most areas with composite materials of aluminium matrix. There are various mechanical studies and analysis that have been done such as, tensile, impact by displacement, and hardness. This simulation analysis have been performed through simulation software that have many features and capable to run testing, which is ANSYS workbench. Moreover, the design of the different types of samples are drawn by using SolidWorks 2019. Then the results of Al/Gr composites are compared for tensile properties
Extraction of biological apatite from cow bone at different calcination temperatures: a comparative study
The purpose of this study is to extract natural hydroxyapatite (HAP) from cow bone. The hydrothermal method followed by calcination treatment at different temperatures is used in this current research. Cow bone has the potential for producing hydroxyapatite, a chief component present in bone and teeth of vertebrates. HAP is an excellent material used in bone restoration and tissue regeneration. Characterizations of the cow bone natural HAP powder were done by X-ray diffraction (XRD) and Thermogravimetric analysis (TGA). TGA data revealed that biological apatite is thermally stable at 1100ºC. XRD data showed that the extracted HAP is, highly crystalline and hexagonal crystal structure having a crystallite size in the range of 10-83 nm. The extracted HAP material is found to be thermally stable up to 1300ºC
FTIR and XRD evaluation of magnesium doped hydroxyapatitesodium alginate powder by precipitation method
Composites material were developed to acquire the desired material properties for biomedical applications in the recovery of defect bone by using Mg-doped HA/SA. Hydroxyapatite (HA) is the major constituent and essential component in bone and teeth. The stability of Mg-doped HA/SA is influenced by starting precursor powders, preparation condition and method of preparing the samples for implant materials. The precipitation method was employed to prepare Mg-doped HA/SA powders by varying the composition of Mg at temperature 1300°C. The influence of Mg-doped HA/SA on phase composition, chemical structure and a functional group at various weight percentages (0.5wt%-1.5wt %) were accomplished through X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) analyses. Based on the XRD and FTIR analyses, there is the presence of different peaks intensity and adsorption bands which indicates the shifted of peaks due to the doping process and a chemical interaction were observed between the inorganic and organic phase. Furthermore, the transformation of β-TCP due to increase in sintering temperatures are caused by the presence of magnesium ions. The OHstretching bands of HA/SA are traced by FTIR that identified the decomposition of Mg-doped HA/SA
Solar-powered aquaponics prototype as sustainable approach for food production
This paper presents the establishment of a solar-powered aquaponics prototype as a sustainable, cost
effective and environmentally sound approach for food production. In this study, a prototype bench
top aquaponics rig with an integrated 20 W solar panel were fabricated for the cultivation of red
Hybrid Tilapia (Oreochromis spp.) and leaf mustard (Brassica juncea). The size of the fish tank is about
29.5L and serves as the base for the setup. Additionally, the hydroponic grower compartment (0.45 m
(L) � 0.32 m (W) � 0.13 m (H)) was stacked on top of the fish tank and was filled with LECA media
bed for the plant growth. Two important operating parameters were studied. First, the amount of energy
produced by the solar panel and the energy consumption by the water pump used in the setup. Secondly,
the resultant effects from fish cultivation and plants growth on the water qualities and nitrification effi�ciency of the aquaponics unit. The aquaponics unit was operated for a month and the values of pH, tem�perature, and ammonia level were measured to be within the range of 6.4–7.2, 27.1–31.7 �C, and
1 mg�L�1
, respectively. Survival rate for fish was about 75% with specific growth rate (SGR) of 3.75%
per day and food conversion ratio of about 1.15. A slight nutrient deficiency was evident and plants
showed a healthy growth with height gain as high as 5 cm was achieved. Despite raining season, our data
shows that the energy produced via 20 W solar panel enabled the unit to run at night without depending
on local electricity for nearly two hours. Clearly, a larger solar panel is needed for longer operation.
Nevertheless, the study has proven the potential of operating a low cost aquaponics setup using renew�able energy for a sustainable food production method
Natural Hydroxyapatite Extracted From Bovine Bone
The aim of this study is to extract natural hydroxyapatite (HAP) from bovine bone. Hydrothermal method followed by calcination treatment at different temperatures is used in this current research. Bovine bone has potential for producing hydroxyapatite, a chief component present in bone and teeth of vertebrates. HAP is an excellent material used in bone restoration and tissue regeneration. Characterizations of the bovine bone natural HAP powder were done by scanning electron microscopy (SEM), Fourier transforms infrared (FTIR) and energy dispersive x-ray (EDX) spectroscopy. The FTIR result confirms the presence of phosphate (PO4-3), hydroxyl (OH)- and carbonate (CO3-2) groups in the powder. SEM displays the surface morphology whereas EDX provides calcium (Ca) to phosphorous (P) ratio in the HAP samples. The results of the EDX analysis indicate that the Ca/P ratio of HAP varies from 1.67 to 1.83. The extracted HAP material is found to be thermally stable up to 1100ºC
Relationship between musculoskeletal symptoms and ergonomic risk factors among office workers
This cross-sectional study aimed to identify the prevalence of musculoskeletal disorders, ergonomic risk levels, and identify ergonomic factors in computer workstation. A questionnaire-based interview and painself report form of the workers were collected among 76 office workers using Nordic Musculoskeletal Questionnaire (NMQ) and direct observation using Rapid Office Strain Assessment (ROSA) to determine ergonomic risks. The mean age for men was 37.0 (SD = 9.4) and women was 34.3 (SD = 8.7). While for the total mean number of working experience was 10.0 (SD = 7.7). The highest prevalence rate of musculoskeletal symptoms among office workers were in the lower back (53.9%), neck region while women had 58.6% musculoskeletal pain on the shoulder region over the last 12 months. From logistic regression analysis, chair height score and back support score were significantly associated with low back pain
Characterization of calcium carbonate extracted from eggshell waste at various calcination temperature
An efficient method to waste utilization is to successfully transform it into high value products. Chicken eggshell contain potential useful minerals of calcium carbonate in which can be processed into biomaterials used in biomedical application. The objective of this study is to derived calcium carbonate from eggshell and analyze the effect of various calcination temperatures on the properties of calcium carbonate. Fourier transform infrared (FTIR) spectroscopy indicates that all calcined samples reveals calcium carbonate is no longer present after calcination as it is already converted to calcium oxide. This also supported by x-ray diffraction (XRD) graphs notably on 900°C. Scanning electron microscopy (SEM) and particle size analysis are applied to determine morphological properties and mean sizes of particles for both raw and calcined samples
Effect of Sintering on Hydroxyapatite/Sodium Alginate Properties
In the present work, a precipitation method was used to prepare a nanocomposite powders consisting of hydroxyapatite and sodium alginate by varying the composition of sodium alginate. The characterization of powder are analyzed by using Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD). SEM is used to identify the morphology and agglomeration of powder while, XRD analysis is used to identify the phase of samples with an increase in the composition of sodium alginate up to 10%. Green samples were prepared and sintered at temperature 1000ËšC and 1100ËšC and the sintered samples are studied based on their phase stability, density and Vickers hardness .The result indicates that there is no secondary phase change happen in this XRD result. The density of HA/SA are increasing relative to hardness for composition ratio 99.5/0.5%. The maximum density were attained by 99.5/0.5% (HA/SA) at 2.12g/cm3 and 2.16g/cm3 for 1000ËšC and 1100ËšC respectively while, the maximum hardness were also attained by 99.5/0.5% for temperature 1000°C and 1100°C at 0.53GPa and 0.62GPa respectively. FESEM images of pure hydroxyapatite are fully disbursed in sodium alginate and the particles size are in agglomerate conditions.Â
Thermogravimetric analysis of polyhydroxyalkanoates (PHA)/nano-calcium phosphate (nCaP)/chitosan biocomposite for heat-related manufacturing process
Nowadays, the adaptability of biodegradable Polyhydroxyalkanoates (PHA) polymer has been thoroughly
assessed to its full potential including shape, mechanical characteristics, thermal properties and biocompatibility.
Additionally, PHA has been produced as biomaterials with potential applications in bone regeneration. Similar to the
mineral apatite found in human bones, nano calcium phosphates (nCaP) are minerals that are necessary for tissue
development and cell adhesion, which have an impact on newly formed apatite. This study aims to investigate the influence
of additives on thermal stability of biocomposite via thermogravimetric analysis (TGA) machine. PHA pellets were mixed
with nCaP as filler ranging from 3-15wt% and 10wt% of chitosan binder via conventional melt compounding. Thermal
analysis showed that the addition of bio-filler improves thermal stability of PHA with highest onset temperature recorded
at 208.1°C. Morphological analysis showed that the addition of nCaP and chitosan alters the flow characteristics of the
composite resulting in surface roughness. Subsequently, in order to prevent the biocomposite from decomposing, all heatrelated
activities particularly those involving machining, it is recommended to perform at temperatures that do not exceed
the onset temperatur
Physicomechanical properties of nanobiocomposite composed of polylactic acid and biogenic nano hydroxyapatite
In the current paper, nanobiocomposite consisting of polylactic acid (biodegradable) (PLA) and nanohydroxyapatite (bioactive) (n-HAP) extracted from bovine bone was fabricated through melt mixing and injection moulding technique for biomedical applications. Partially biogenic nanohydroxyapatite was obtained from bovine bone by hydrothermal method and calcination treatment without using of any chemicals/solvents. Physicomechanical properties of neat-PLA and PLA/n-HAP nanobiocomposite were evaluated using X-ray diffraction (XRD), universal testing machine (UTM) and scanning electron microscopy (SEM). XRD result showed that the intensity of n-HAP peaks increased in the nanobiocomposite as n-HAP-900 loading increased. Tensile strength decreased with increasing the n-HAP-900 loading from 56.78 to 48.25 MPa due to poor interfacial adhesion between neat-PLA and n-HAP. PLA/n-HAP with 1% loading exhibits tensile strength potential for bone implant application and can be promising biomedical materials for orthopedic applications
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